Loudspeaker installation for automotive radio sets



Feb. 2, 1937. R. J. ROCKWELL LOUDSPEAKER INSTALLATION FOR AUTOMOTIVE memo SETS Filed July 24, 1935 INVENTOR fl N/IL a JROcKWELL.

ATTORNEYJ,

Patented Feb. 2, 1937 f UNITED STATES PATENT oFHca-f; Ronald J. Rockwell, Cincinnati, Ohio, assignor to The Crosley Radio Corporation, Cincinnati,

Ohio, a'corporation of Ohio I Application-Filly 24,1935, Serial No. 32,935

4Claims. (61296-1) For the most part in the past the loud speakers of automotive radio sets have been installed benea'th the dash. Some work has recently been doneon the installation of loud speakerselsewhere, and in particular beneath the roof of the vehicle. My present invention relates to the latter type of installation, and has for its; fundamental object the provision of improvements in construction whereby the operating eiilciency and the response of a loud speaker installation may be very greatly improved. This and other obiectsof my invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction and arrangement of parts of which I shall hereinafter describe an exemplary embodiment. For the sake of clearness, reference is now made to the drawing, wherein:

Figure 1 is a perspective view of the top of a vehicle with roof portions cut away showing a mounting means for a loud speaker.

Fig. 2 is a sectional view along the median longitudinal line of the vehicle showing the installation.

In the practice of my invention I install a loud speaker in a vehicle beneath the roof or in a wall, or back of the front seat thereof in such a way as to secure not only adequate bailling, but also a resonating effect which greatly improves the loud speaker performance. In doing this I mount a plate or a panel of the material for example along the roof line of the vehicle and cause it to be interspaced from overlying parts. This panel is perforated for the reception of a loud speaker which is set into the perforation, preferably, though not necessarily, with the cone of the speaker extending downwardly beyond the panel. Behind the panel thereof there is a hollow space acting as a resonator. Preferably the loud speaker is located centrally of the panel. Preferably also the panel is left open at one end, as I shall hereinafter set forth. Thus there is provided essentially a double resonator, one portion of whch is closed and the other portion of which is open. The resonating action of the closed half of the structure reinforces the bass frequencies, while the open half of the resonator construction has fundamentally a somewhat higher frequency, and helps to reinforce the medium frequencies of the loud speaker output. Thus the performance of the speaker is very greatly enhanced. In Fig. 1, at I, I have shown an automobile body. For the sake of clarity, the outer roof covering portlons have been cut away, but roof truss members are indicated at 2 and 3. I have indicated at 4 can be substituted for a my panel mounted there-below, and ati an opening therein to receive the loud speaker.

In Fig. 2 the line. of the top. covering ofzthe roof is indicated at B. My panel 4 is preferably made of a stiff material, such as cardboard. orv any of 5 the panel-like substances whichv are available on I the market, and including,-but without limitation, masonite and the like. The panel is preferably attached to and supported by roof stringers indi-. cated at 2 and i; so that there is a substantial resonator space behind the panel. Preferably also the panel extends from one side of the vehiclesubstantially to the v other, although, of course, resonating effects may be otherwise obtained. It is my practice to attach my panel not only to the stringers 2 and 1, but also to an end frame member indicated at 8 in Fig. 1, at one end. At the other end the panel preferably terminates short of the opposite end stringer as indicated at 9 in Fig. 1, leaving this end of the resonator structure open for purposes which have been described.

I have indicated the field of the speaker at Ill in Fig. 2, extending through the perforation 5 in the panel. I have indicated the cone of the speaker as being reversed, and extending downwardly from the panel as at l I. A shield or guard l2 may be placed over the cone. It will be understood that this particular structure is not a necessary limitation on my invention. The cone may be reversed from the position shown and may extend partially within the perforation in the panel.

In any eventphowever, the perforation in the panel is of such size as to permit the space behind the panel to be responsive to vibrations of the air setup-by the reverse side of the cone. The actual mounting of the loud speaker struc ture to the panel may be effected in any. one of a large number of ways which are within the skill of the worker in the art to adapt to his use. Also the novel structure which I have herein described may be placed in other parts of the vehicle than that specifically shown in my drawing.

It will be noticed particularly in Fig. 2 that the panel 4 lies substantially in the plane of the interior roof trim of the motor vehicle. It

corresponding portion of this inner covering or trim, and when so su stituted can be decorated in any way desired suitable to the interior finish of the motor vehicle. In some instances the trim or interior covering may be caused to extend over the panel, being suitably perforated at the place of mounting of the loud speaker, and suitably perforated also at the open end of the resonator construction, where it will be held to the edges of the various parts by any suitable type of fastening.

Modifications may be made in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire to secure by letters Patent, is:-

l. A loud speaker construction for vehicles having aroof, comprising a panel, means for interspacing said panel from said roof, said panel having an opening. and a loud speaker attached to said panel at said opening in such away as tomake theaironbothsides of said panelresponsive to vibrations set up by said loud speaker, said panel being of elongate shape and forming with said roof a resonator closed at least at its sides by members interposed between said panel and said roof which members constitute a means for inter-spacing said panel from said roof, said panel being also similarly closed at one end, but open at the other end.

2. In an automotive vehicle having a roof, an interior roof panel of relatively stiif material, means interspacing said panel from said roof, said panel extending from one side of said automotive vehicle across and beneath said roof near- 1y to the other side thereof so that said panel encloses a space beneath said roof at all portions thereof excepting at one end, a substantially centrally located perforation in said panel, and a loud speaker mounted in said perforation so that the vibrating element thereof 'is effective upon theairon bothsidesofsaidpanel.

3. In combination in a vehicle having a roof with stringers, an outer covering thereon and an inner or a finish covering attached to said said inner covering, said panel being perforated,

a loud speaker mounted. to said panel and so located with respect to said perforation that" the vibrating element thereof is eflective upon the air on both sides of said panel, said panel extending across said vehicle laterally to one side thereof so as to close the space behind said panel on said one side, said panel however, being displaced a slight distance from the opposite side of said vehicle, whereby said panel is adapted to produce a dual resonating effect, the closed portion of said panel reinforcing the lower frequencies and the open portion of said panel reinforcing higher frequencies.

4. In combination in a vehicle or the like, a sound reflective wall, a panel of relatively still. sound reflecting material, said panel constituting a loud speaker mounting and being substantially centrally perforated to accept a loud speaker in such a way that the air on both sides of said panel will be responsive to air vibration set up by said loud speaker, and said panel being of elongated shape. and extending on opposite sides of said loud speaker at least as great a length as the diameter of said loud speaker, means interspacing said panel from said wall and extending along the elongated sides of said panel so as to close said sides and form with said panel and said wall a resonating space located behind said loud speaker, and means closing off said resonator at one end, the other end thereof being open.

RONALD J. ROCKWELL. 

